Hmm ... is this different than the release which added Vudu in the US? We've had DLNA for a month I think with REL09. In the notes for REL10 it says:

"Adds support for the Media player / Socialife™ application and WPS2.0 functionNote: The Media player application only supports local contents (Internal Memory and USB). This application is not supported using DLNA® technology."

I was sure I used DLNA with Media Player for non local content.

I have noticed that ViMu has become really less than optimal when used as an external player for Mijuu. There doesn't seem to be a good video player for the GTV other than the Plex one at this time. In particular ViMu won't play many of my m4v files, something Plex handles easily.

I like ViMu a lot. It's very quick and remembers your position in your movie. You can even just access a file share which is faster than going through a DLNA server. Plex is very clunky by comparison. But a lot depends on how you have things setup. If you re-encode your problematic videos to a format that ViMu can play, clearly you won't experience play back issues. If you organize your media library in a manner that Plex likes, it won't seem nearly so clunky.